NNLL top-antitop production at threshold
Maximilian Stahlhofen, André H. Hoang · 2013
We present an update to the NNLL RG-improved QCD prediction of top-antitop production in e + e -annihilation at threshold.It includes for the first time a complete NNLL resummation of ultrasoft logarithms, which are dominant at this order and give a sizable correction.The renormalization scale dependence of the total resonance cross section decreases substantially compared to earlier predictions, where the ultrasoft logarithms were included only partially.